P0182 Code: Fuel Temperature Sensor A Circuit Low
The fuel temperature signal is pulled close to 0 V, so the engine computer thinks the fuel is extremely hot.
Safety first · Consult a professional
- Fuel vapor is flammable. No smoking or open flames; work outdoors and fix fuel leaks before driving.
At a glance
Severity: Low
- Meaning
- Fuel Temperature Sensor A Circuit Low
- System
- Fuel & Air Metering · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $40–$1,000
- DIY difficulty
- Moderate
The PCM feeds the fuel temperature thermistor through an internal resistor from a 5 V supply and reads the voltage left over. Hot fuel lowers the sensor's resistance and pulls that voltage down, so a signal stuck near zero looks like fuel at 250 °F or more. P0182 sets when the voltage drops below the lowest value a real sensor can produce, which almost always means the signal wire is touching ground somewhere or the sensor has shorted internally. On a diesel, a fuel temperature that high tells the ECU to protect the high-pressure pump and injectors, so many diesels cut power noticeably. On gasoline engines the effects are milder: the EVAP leak test is suspended and some returnless systems raise fuel pressure to fight vapor that isn't there.
Can I keep driving? Gasoline cars normally drive fine. On a diesel the ECU may limit power as if the fuel were overheating, so plan merges and passing with that in mind and get the wiring checked soon.
How to read P0182
- P Powertrain
- 0 Generic (SAE)
- 1 Fuel & air metering
- 82 Specific fault
Symptoms
- Check engine light on
- Diesel: reduced power or limp mode even with cool fuel
- Fuel temperature in live data shows an impossible value, often 250 °F or more on a cold morning
- EVAP monitor does not run, so the car shows not ready at inspection
- Code sets after rain, a car wash or driving through deep water, then may clear itself
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Signal wire chafed through and touching ground: tank strap, frame rail, filter bracket or exhaust heat shield
- Water in the connector bridging signal to ground, often at an underbody or tank-top plug
- Sensor shorted internally
- Harness pinched when the tank, fuel filter or pump was reinstalled
- PCM input circuit fault
Diagnosis step by step
Confirm the reading in live data
Compare fuel temperature with intake air temperature on a cold engine. A fuel value that is 200 degrees hotter than the air, with the engine not yet started, confirms a low-voltage fault rather than genuinely hot fuel.
Tools: OBD-II scanner
Unplug the sensor and watch the value
With the key on and the scan tool connected, disconnect the sensor. The reading should snap to its coldest value, often -40 °F. If it does, the harness is fine and the sensor itself is shorted. If it still reads hot, the short is in the wiring between the connector and the PCM.
Tools: OBD-II scanner
Measure the sensor resistance
A healthy sensor at room temperature usually reads a few thousand ohms. A reading of a few ohms, or continuity from either pin to the sensor body on a two-wire sensor, confirms an internal short.
Tools: Multimeter
Find the short in the harness
Disconnect the battery, the sensor and the PCM connector, then measure between the signal wire and chassis ground. It should read open. If it shows continuity, move along the harness, flexing it at tank straps, clips and brackets until the reading changes.
Tools: Multimeter, Flashlight
Inspect connectors for water
Open the sensor plug and any inline connectors under the car. White or green corrosion between terminals, or a missing seal, lets water bridge the signal to ground. Dry, clean and reseal, then recheck the value with the sensor plugged in.
Tools: Screwdriver, Flashlight
Where the parts are
- 1Gas cap
- 2Charcoal canister
- 3Purge valve
- 4Vent valve
- 5Fuel pump
- 6Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Repair chafed signal wire and re-route or protect the harness | Yes | $90–$300 |
| Dry, clean and reseal a water-damaged connector | Yes | $40–$180 |
| Replace fuel temperature sensor (filter housing or fuel line) | Yes | $80–$250 |
| Replace in-tank sender with integrated sensor | No | $350–$1,000 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Emissions / smog test impact
Will fail
A stored P0182 with the check engine light on fails an OBD-II smog check. Because the fault also blocks the EVAP monitor on many gasoline cars, expect to drive for several days after the repair before the car reads ready.
Frequently asked questions
Why does a short circuit make the fuel look hot?
The sensor's resistance drops as fuel warms, which pulls the signal voltage down. A wire touching ground pulls it down all the way, and the PCM translates that into the hottest temperature on its table.
My diesel lost power and shows P0182. Is the injection pump damaged?
Unlikely. The power cut is a protection strategy triggered by the false hot reading, not a sign that the fuel really overheated. Fix the short and the power normally returns immediately.
The code comes and goes with the weather. Why?
Moisture is the likely trigger. Water in a poorly sealed connector or on a chafed wire creates a path to ground when the car is wet and dries out later. Inspect every plug between the sensor and the PCM, especially under the car.
Can I just unplug the sensor to get rid of the power loss?
That swaps P0182 for P0183, and the ECU then uses a default value. Some diesels run acceptably that way, but the check engine light stays on and the car fails inspection, so it is a stopgap only.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- Manufacturer public service information (cross-checked)
- Methodology: How We Build Code Pages · Data Sources We Use · Editorial Policy